X100 AF Slow: Frustating

I tried to photograph my friends during a performance called murga, where they dance without stopping. It was difficult, I had to work in advance, camera was not fast enough

My x100 set up: afs-c, jpg + raw, ovf, iso auto, aperture auto. the sd card is a sandisk 45 mb/s 8gb.

any advice?

I hope the next firwmare will improve af permormance or i will look for a faster camera

thanks

paolo

ps: sorry for my english